Vega has lived in the valley her whole life—forbidden by her mother to leave the safety of its borders because of the unknown threats waiting for her in the wilds beyond. But when Vega sees an omen in the sky—one she cannot ignore—she is forced to leave the protective boundaries of the valley for the first time. Yet the outside world is much more terrifying than Vega could have ever imagined. People are gravely sick—they lose their eyesight and their hearing, just before they lose their lives. But Vega has a secret: she is the Last Astronomer—a title carried from generation to generation—and she is the only one who understands the knowledge of the stars. Knowledge that could hold the key to a cure. So when locals spot the tattoo on Vega’s neck in the shape of a constellation—the mark of an astronomer—chaos erupts. Fearing for her life, Vega is rescued by a girl named Cricket who leads her to Noah, a boy marked by his own mysterious tattoos. On the run from the men hunting her, Vega sets out across the plains with Cricket and Noah, in search of a fabled cure kept secret by the astronomers. But as the line between friends and protectors begins to blur, Vega must decide whether to safeguard the sacred knowledge of the astronomers...or if she will risk everything to try to save them all.